This invention relates to laparoscopic staplers, and in particular to an overload sensor and lockout for laparoscopic staplers.
Laparoscopic surgical techniques have greatly reduced the trauma and risks associated with certain surgeries, and have expedited patient recovery and reduced scarring. However, laparoscopic surgical techniques also present many challenges to the surgeon. The surgeon must perform delicate procedures with a limited view of the surgical site. The surgeon is separated from the surgical field, and cannot always rely on the sense of touch. One area that can be particularly challenging is in the use of laparoscopic staplers. These staplers typically include jaws which gather or approximate the tissues to be stapled, and a staple forming apparatus which forms a staple in the tissues approximated in the jaws. An example of such a stapler is disclosed in Green et al., U.S. Pat. No. 5,040,715, incorporated herein by reference. In using laparoscopic staplers, the surgeon does not have an ideal, three dimensional view of the tissues being stapled as compared to some open surgical techniques, and receives only limited tactile feedback of the tissues being approximated in the jaws by the operation of the instrument. Thus, it is possible for the surgeon to occasionally gather excessive tissue between the jaws of the stapler. If there is excessive tissue between the jaws, there is a risk that the stapler could be damaged, or that if a staple is placed it will not be properly formed or will not adequately hold the tissue. Thus, the surgeon must proceed slowly and deliberately to anticipate the potential for approximating an excess quantity of tissue between the jaws of the stapler.